Steve Ott gave Buffalo the lead for good when he batted a rebound out of the air past Pittsburgh's Marc-Andre Fleury with 2:34 left and Vanek added an empty-netter in the final minute.

Jochen Hecht also scored for the Sabres, who never trailed while snapping the Penguins' seven-game winning streak.

Chris Kunitz scored his 22nd goal for Pittsburgh and Jarome Iginla scored in his fourth straight game but it wasn't enough. Fleury made 29 saves but failed to pick up his 23rd win of the season.

Pittsburgh center Evgeni Malkin assisted on Iginla's goal to pick up a point in his return after missing four games with a lingering shoulder injury.

The Penguins, the Eastern Conference's top team, seemed to have things under control after Iginla tied the score 11:02 into the third period. Buffalo, already eliminated from playoff contention, kept battling.

Ott put the Sabres ahead to stay with his ninth goal of the season. Officials spent more than a minute reviewing the score to see if Ott's stick was too high.

The call stood and Vanek threw in an empty-netter to give the Sabres their second straight win over Pittsburgh.

The Penguins again played without center Sidney Crosby, who remains out with a broken jaw.

Still, Pittsburgh appeared energized by the return of the league's reigning MVP and dominated the early stages with Malkin looking in top form despite playing the first time in nearly two weeks. Buzzing the net with regularity, Malkin's teammates seemed intent on setting him up for his ninth goal of the season.

Instead, the Sabres, playing for little, struck first.Vanek put Buffalo up 12:49 into the game with a one-timer from between the circles thanks to a pretty feed from behind the net by Cody Hodgson.

The momentum lasted all of 20 seconds, or as long as Kunitz needed to take a pass from Brandon Sutter then wrist a shot off Miller's glove and into the net to tie the score.

Buffalo appeared to go up 2-1 just over six minutes into the second but the referee waved off Andrej Sekera's goal after ruling Vanek interfered with Fleury. Vanek nearly got his revenge at the end of his penalty, streaking out of the box for a breakaway on Fleury only to see the goaltender get a piece of the puck with his glove to send it out of harm's way.

The Sabres did pull ahead when Hecht beat Fleury with a shot from just inside the left faceoff dot 6:11 into the third. The Penguins, with nothing to play for other than an outside chance of catching the Blackhawks for the league's best record, appeared ready to end a three-game in four-day stretch until Letang found Iginla standing by himself at the top of the left circle. Iginla responded with a slap shot that powered its way by Miller for Iginla's fifth goal with Pittsburgh since coming over in a trade from Calgary last month.

NOTES: Crosby, defenseman Paul Martin (upper body injury) and forward James Neal (concussion) all skated on Tuesday, though there remains no timetable for their return. Pittsburgh coach Dan Bylsma indicated earlier in the week Martin could be back before the end of the regular season on Saturday ... Pittsburgh plays in New Jersey on Thursday ... Buffalo ends the season at home against the New York Islanders on Friday.